Evaluating the effects of six essential oils on fermentation and biohydrogenation in in vitro rumen batch cultures

Abstract

Conjugated linoleic acids (CLA) have recently attracted significant attention because of their health benefits in a variety of models of metabolic and chronic inflammatory diseases. Among the many CLA isomers, c9t11 CLA has received the most attention because of its recognized health benefits as a cancer chemopreventive (Kennedy et al., 2010;Crumb 2011). The c9t11CLA is synthesized either in the rumen as an intermediate during the biohydrogenation of linoleic and linolenic acids (Harfoot and Hazlewood, 1987;Lee and Jenkins, 2011) AbstrAct: The effects of six essential oils (EO) on rumen fermentation and biohydrogenation were evaluated under in vitro conditions. Three doses (125, 250, and 500 mg/l) of EO were evaluated using in vitro 24 h batch culture of rumen fluid with a 55 : 45 forage : concentrate diet. Treatments were control (CON), control with Siberian fir needle oil (FNO), citronella oil (CTO), rosemary oil (RMO), sage oil (SAO), white thyme oil (WTO), and clove oil (CLO). Treatments were incubated in triplicate in 125 ml flasks containing 500 mg of finely ground total mixed ration (TMR), 25 mg of soybean oil, 10 ml of the strained ruminal fluid, 40 ml of media, and 2 ml of reducing solution. After 24 h, the pH was determined and samples were collected to analyze ammonia N, volatile fatty acids (VFA), and fatty acids (FA). Cultures pH was not affected by EO averaging 6.6 ± 0.2. In general, high EO doses reduced the total VFA concentration except for SAO and RMO. Relative to CON, all EO decreased (P < 0.05) ammonia N concentrations except for the highest dose of WTO. Except for SAO, EO did not modify acetate to propionate ratio. Relative to CON, the addition of CTO and FNO increased (P < 0.05) the proportions of isobutyrate and decreased (P < 0.05) the proportions of valerate and isovalerate. The concentrations (mg/culture) of C18:0 and C18:1 trans FA decreased (P < 0.05) with CTO, FNO, RMO, and SAO relative to CON. Most tested EO in this study had little to no effects on conjugated linoleic acids (CLA), and linoleic and linolenic acids concentrations. In conclusion, results from this study showed that except for effects on ammonia N, EO tested in this study had moderate effects on rumen fermentation. The reduction in the formation of trans FA and C18:0 with some EO may indicate shifts in the biohydrogenation pathways toward the formation of other unidentified intermediate FA. Keywords: plant extracts; volantile fatty acids; trans fatty acids; in vitroAbbreviations: CLA = conjugated linoleic acids; CLO = clove oil; CON = control; CTO = citronella oil; EO = essential oils; FA = fatty acids; FNO = Siberian fir needle oil; RMO = rosemary oil; SAO = sage oil; TMR = total mixed ration; VFA = volatile fatty acids; WTO = white thyme oil

Evaluation of the Effect of Four Essential Oils as Potential Alternatives for Monensin on Rumen Fermentation Characteristics and Nutrient Degradability

“…Compared to monensin, the four tested EOs at a concentration of 45 µl significantly reduced the NH 3 -N concentration (Table 6). A similar trend was previously noted with other EOs, such as clove oil (Gunal et al, 2013), eugenol (Busquet et al, 2006;Castillejos et al, 2006), Eucalyptus citriodora, and Ocimum gratissimum (Kouazounde et al, 2015). However, according to Castillejos et al (2008), 500 mg/l clove oil had no influence on NH 3 -N concentrations.…”

“…However, according to Castillejos et al (2008), 500 mg/l clove oil had no influence on NH 3 -N concentrations. The small effects of P. guajava, P. graveolens and C. citratus EOs on the NH 3 -N concentration may be due to the collaboration between their active components and proteins (Gunal et al, 2013). Nonetheless, the strong suppressive effect of C. nardus EO on ammonia production could probably result from the reduction in hyper-ammonia producing bacteria such as Peptostreptococcus anaerobius and Clostridium sticklandii due to the antimicrobial activity of its major component geraniol (McEwan et al, 2002).…”

Perfil metabólico de isómeros de Ácido Linoleico Conjugado y calidad de ovocitos en ovejas de pelo

“…Por su parte, AbuGhazaleh y Holmes (2007), informan que la biohidrogenación del ácido linoleico es más eficiente en la producción de C18:1, lo cual podría explicar por qué se registran niveles más altos de CLA cuando se utiliza aceite de origen vegetal rico en ácido linoleico. Sin embargo, es importante analizar el contenido de ácidos grasos de los aceites a utilizar, ya que su contenido puede influir en el proceso de biohidrogenación y cambiar las rutas hacia la formación de otros intermediarios (Gunal et al, 2013), lo que podría dificultar la determinación del verdadero origen de los intermediarios específicos de dicho proceso (Jenkins et al, 2008).…”

Effect of evening primrose oil on biochemical parameters of thoroughbred horses under maximal training conditions

“…Dietary administration of essential oils and unsaturated fatty acids was used for the treatment of canine atopic dermatitis and other serious illnesses (hyperlipidaemia, cardiovascular, renal, and neurological diseases), with positive results (Tretter and Mueller 2011;Gunal et al 2013;Kubelkova et al 2013;Lenox and Bauer 2013). Furthermore, the positive effect of PMO on ruminal fermentation activity was monitored in beef cattle, sheep, and goats (Varadyova et al 2007;Cieslak et al 2009;Szumacher-Strabel et al 2009), and in addition its effect on fatty acids in muscle tissue, sperm fertility and motility was observed in poultry (Cerolini et al 2003).…”